verybody loves a spreadsheet, right? Well the Inca had their own version of a spreadsheet, and it is likely a major factor in why the Inca empire could expand so rapidly and so successfully. And also, it was done by tying knots in series of strings. The khipu is an ingenious alternative device to a counting system, first introduced by the Wari and developed by the Inca. It was made up of a series of coloured, twisted and knotted cords that stored information, like the number of people in a community or the amount of food harvested. Honestly, the verdict is still out on exactly how these were used, but we do know from Spanish chronicles that they were also used to record histories, poems and even songs.